This invention relates to mobile lifts and more particularly to wheeled lifts having an elevatable platform with a hoist for rescuing a human from an enclosure; as well as lowering a human into and removing a human from an enclosure.
Mobile lifts have been used to elevate materials and workmen for a variety of purposes. One such lift includes a chassis mounted on four wheels with one section of an extension ladder rigidly supported on the chassis at an obtuse angle. An extensible section of the ladder supports a horizontal work platform. A hand winch is used to elevate and lower the extensible section of the ladder with the supported work platform. The work platform extends beyond the chassis of the mobile lift to permit placement of material or personnel beyond the area in which the wheeled chassis is free to travel. The platform may include a vertical entryway to permit access to the top opening of a container when the platform rests on the container with the entryway aligned with the top opening. Although these previously designed mobile lifts are advantageously used in numerous applications, there remains a need for equipment to quickly aid in rescue of incapacitated personnel from enclosures, such as storage tanks.
The present invention is directed to providing a mobile human lift unit for rescuing personnel from enclosures. An overhead hoist is mounted on an elevatable platform having a vertical entryway. The overhead hoist includes a winch having a cable reeved on an overhead pulley with its free end attachable to a human lift harness or the like. The rescue equipment is mobile to permit it to be quickly positioned to effect a human rescue operation. The platform is vertically adjustable to correspond to the height of a variety enclosures. The overhead hoist may take the form of a tripod, an overhead track and dolly or an overhead crane. The use of an overhead crane which pivots about a vertical axis, facilitates lowering of a rescued person to the ground.